INTRODUCTION

What is filler Slab? Filler slab is basically a solid reinforced concrete slab with partial replacement of concrete in the tension zone by the filler material . Normally in design of solid slab we assume , concrete below neutral axis does not carry any load and it only adds to the weight of the slab. Here , in the tension zone , concrete is replaced by filler materials such as Mangalore tiles , stabilized mud blocks, specially prepared cement cups, burnt bricks , hollow concrete blocks etc,.

Details of some typical filler materials

Construction of filler slab using SMB

Ceiling of SMB filler slab roof before finishing

Mangalore tile as filler material

Specially prepared cups

Bricks as filler material

Concrete blocks as filler material

As concrete in tension zone is replaced by filler material of lesser density, dead weight of the slab is reduced.

Eg. For a room size 3m x 4m ,reduction in the dead weight by replacing concrete using different filler materials 1.Stabilized mud blocks - 15.02% 2.Mangalore tiles 19.66% 3.Burnt bricks 20%

Advantages. Less steel and cement.Better thermal insulated and sound insulated.Less dead weight.Saving of about 30%dead weight of the slab.Aesthetically pleasing ceiling pattern.Cost effective.

Comparison between the conventional and alternative roofing systems, in terms of volume of concrete required for a plan area of 4.5m x 4.5m (effective).

CONCLUSIONAlternative roofing system provides economic solutions to roofing of houses,especially in case of mass housing projects.Of late, due to unlimited construction activities the construction materials are dwindling at a faster rate. This warrants the application of research efforts to alternative building materials and systems.

Cement is an energy intensive materials any replacement of cement are concrete will help to save precious raw materials and reduce the environmental pollution.One additional feature of filler slab is that it provides an aesthetic ceiling surface while making the roof insulated against the heat. The savings in volume of concrete will be larger than the cost of replacing concrete by means of filler materials.